Magnetic wrench having its magnet inwardly spaced from its nutengaging socket by a hollow magnetic sleeve



F. G. CLARK Aug. 9, 1955 MAGNETIC WRENCH HAVING ITS MAGNET INWARDLYSPACED FROM ITS NUT-ENGAGING SOCKET BY A HOLLOW MAGNETIC SLEEVE Fil dOct 6 1954 N ulmlll INVENTOR. ff'eaenc/z G CZar/ic BYM I A? 44%;

Frederick G. Clark, Butfalo, N. Y., assignor of one-half to WadeStevenson, Buffalo, N. Y.

Application October 6, 1954, Serial No. 460,675

Claims. (Cl. 81-125) This invention relates to a magnetic socket wrenchand more particularly to a socket wrench in which a magnet is utilizedfor holding a nut in position in said wrench for threading onto a boltor stud, or the like.

An object is to provide asocket wrench of this type in which the magnetis disposed inwardly from the inner limits of a nut-engaging socket soas to be relatively free from the possibility of damage through impact,and yet has its magnetic attraction effectively transmitted to the nutto be held and driven.

Still another object of this invention is to provide a magnetic socketwrench of the character described, which is simple in both constructionand operation and there fore which can be readily manufactured and whichhas high commercial utility.

The present invention is an improvement over the prior art asrepresented by applicants United States patent, Number 2,671,369, issuedMarch 9, 1954, and the United States patent to Ray M. Brown, number2,630,036, issued March 3,1953. In each of these two prior art devices aretractable magnet is provided to permit the work piece to be insertedinto the socket of the wrench to varying depths, while still maintainingcontact with the magnet. Such an arrangement also permits a bolt uponwhich a nut is being driven to protrude into the Wrench as the nut istightened down.

One of the principal objections to socket wrenches of this characterwhich have a retractable magnet is that foreign matter can get into theclearance hole and cause the magnet to stick and therefore render itinoperative as far as its ability to accommodate positions of varyingdepths of the work piece is concerned. In addition, the magnet isordinarily quite brittle and, since it is directly abutted by the boltor work piece, it is easily damaged or actually broken, which, ofcourse, then renders the tool inoperative.

Further objects and advantages of this invention will become evident asthe description proceeds and from an examination of the accompanyingdrawings, which illustrate several embodiments of the invention and inwhich similarnumeralsrefer. to similar parts. throughout the severalviews.

In the drawings:

Figure 1 is a view in elevation and partly in vertical section of oneform of magnetic socket wrench incorporating the invention.

Figure 2 is a plan view from above of the socket Wrench shown in Figure1.

Figure 3 is a plan view from below of the socket wrench shown in Figure1.

Figure 4 is a view in elevation and partly in vertical cross-section ofthe socket wrench shown in Figure l, in operative association with a nutand bolt member.

Figure 5 is a view in elevation and partly in vertical section of amodified form of socket wrench also incorporating the invention.

Referring now to Figures 1, 2, and 3, a socket wrench is shown therein,indicated generally by the numeral 10.

2,714,829 Patented Aug. 9, 1955 This embodiment is shown by way ofexample and includes a shank 12 which is preferably provided with atubular bore 14 through at least a portion thereof. The upper end '16 ofthe shank may have a female square drive opening 18 formed therein,adapted to receive in driving engagement the square end of a drivingtool. An opening 20 may be provided in the end portion 16 to receive aspring pin adapted to keep the shank in place on the driving tool. Theopposite end 22 of the shank may be provided with a socket opening 24which may be hexagonal in cross-sectional configuration, as best shownin Figure 3. Obviously, the openings 18 and 24 could be of any otherdesirable cross-sectional configuration and, as a matter of fact, theupper end 16 of the shank could be provided with a fixed handle similarto that of an ordinary screw driver, if desired. Likewise, the opening24 could be made of any desired cross-sectional configuration adapted tofit the form of fastening device to be driven. Similarly, the bore 14could be other than circular in cross-section if desired, but ispreferably circular.

A shoulder 26 is preferably formed at the inner end of the socket 24 anda sleeve 28 of substantially nonmagnetic material is inserted in thebore 14 so that its lower end 30 issubstantially flush with the shoulder26. A preferably cylindrical permanent magnet 32 is disposed within theupper end 34 of the sleeve 28 while a preferably tubular, hollowextension member 36 of magnetic material is disposed within the end 30of the sleeve 28. The upper end 38 of the extension member 36 ispreferably disposed in abutment with the lower end 40 of the magnet 32,the end 38 in this embodiment preferably being closed. The opposite end42 of the extension member is disposed so that it protrudes slightlyinto the socket opening 24, as shown in Figure l.

The shank 12 is preferably made of a good grade of steel which ishardenable and magnetic. The sleeve 28, as previously stated, is ofsubstantially non-magnetic material, which term is herein used in thepractical sense to designate materials of very low magneticpermeability. The magnet 32 is preferably of the bar type, beingcircular in crosssection and having the opposite poles thereof atopposite ends of the magnet. It is preferably formed of Al-nico alloy orsome similar material with very high magnetic properties.

In actual operation, the size of the tool selected should be such thatit is adapted to receive within the socket 24 the nut to be driven, andthe extension member 36 should have an internal diameter such that thebolt or threaded stud upon which the nut is to be threaded is capable ofbeing received therewithin. The nut to be driven is placed within thesocket 24 in abutment with the outer end 42 of the extension member 36and is maintained in that position by operation of the magnet 32. Thenut may then be driven onto the bolt 48, or the like, and

after it has passed the point where its upper side 44 (as shown inFigure 4) is flush with the upper end 46 of bolt 48, that end willprotrude into the extension member 36. In Figure 4 the nut is shownseated on the bolt 48 which extends through the sheet element 52, thenut 50 having been driven onto the bolt 48 down into abutment with saidsheet. It is clear that if the opening 54 Within the extension member 36were not provided, the end 46 of the bolt 48 would come into abutmentwith a portion of the wrench member and the latter would be displacedfrom its initial driving position with respect to the nut 50. Figure 4therefore clearly illustrates the particular advantage of this type ofconstruction in connection with the driving of a nut onto a bolt, or thelike, to any substantial degree.

As shown in Figure 5, several modifications are possible so as to formalternative embodiments of the invention. For example, the magnet maytake the form shown in Figure 5, which magnet 56 has a lower portion 58of reduced diameter enclosed within the sleeve 60 in the bore 64 of theshank member 62. In such a modification, preferably not more than halfof the length of the magnet 56 should be in contact with the bore 14.Such an arrangement will provide a better path for the magnetic lines offlux than is provided in the form of tool shown in Figure 1.

Regarding this path as a separate magnetic circuit, it is clear that inthe form of device shown in Figure 1, there is a gap in the circuitbetween the upper end of the magnet 32 and the shank 12 since the sleeve28 is formed of substantially non-magnetic material. Actually, this isno real source of difficulty in the form of device shown in Figure 1,since the square end on the driving tool which is inserted in theopening 18 will normally abut the upper end of the magnet 32. In someinstances, however, it may be preferable to provide a more positivecontact between the magnet and the shank such as is achieved in the formof constructio shown in Figure 5.

Obviously, the magnetic circuit in either form of device extends downthrough the shank to the socket opening 24 and thence through the nut orworkpiece received therein and disposed in contact with the extensionmember 36 or 66. This latter member, as previously discussed, serves tocomplete the circuit between the workpiece and the lower end of themagnet.

Likewise, as shown in Figure 5, the extension member 66 may be provided,which differs from the extension member 36 previously described in thatthe upper end 68 thereof is open, as well as the lower end 70.

In the drawing and specification, there has been set forth severalpreferred embodiments of the invention, and although specific terms areemployed, they are used in a generic and descriptive sense only and notfor purposes of limitation. Changes in form and in the proportion ofparts, as well as the substitution of equivalents are contemplated, ascircumstances may suggest or render expedient, without departing fromthe function or scope of this invention as further defined in thefollowing claims.

I claim:

1. A socket wrench particularly adapted for driving nuts on bolts,comprising a hollow shank provided at the outer end thereof with aninternal non-circular bore for receiving the workpiece to be rotated bythe wrench, a sleeve of substantially nonmagnetic material securedwithin said hollow shank, a magnet secured within said sleeve, and asecond hollow sleeve of magnetic material secured within said firstnamed sleeve with one end in association with said magnet and the otherend extending into said non-circular bore, said second sleeve beingadapted to retain the workpiece within said bore through magneticattraction.

2. A socket wrench particularly adapted for driving nuts on bolts,comprising a hollow shank provided at the outer end thereof with aninternal non-circular bore for receiving the workpiece to be rotated bythe wrench,

a sleeve of substantially non-magnetic material secured within saidhollow shank with one end adjacent said noncircular bore, a magnetsecured within said sleeve in spaced relation to said end of said sleeveadjacent said non-circular bore, and a second hollow sleeve of magneticmaterial secured within said first named sleeve with one end inassociation with said magnet and the other end extending into saidnon-circular bore, said second sleeve being adapted to retain theworkpiece within said bore through magnetic attraction.

3. A socket wrench particularly adapted for driving nuts on bolts,comprising a hollow shank provided at the outer end thereof with aninternal non-circular bore for receiving the nut to be rotated by thewrench, a sleeve of substantially non-magnetic material secured withinsaid hollow shank with one end adjacent said non-circular bore, a magnetsecured within said sleeve in spaced relation to said end of said sleeveadjacent said non-circular bore, and a second hollow sleeve of magneticmaterial secured within said first named sleeve, said second sleevehaving a closed end disposed in abutment with one end of said magnet andan open end extending into said noncircular bore and being adapted toretain the nut within said bore, and to receive the end of the bolt,upon which said nut is being driven, within said second sleeve.

4. A bolt clearance socket particularly adapted for driving nuts onbolts, comprising a shank member having a non-circular nut receivingopening at one end thereof, a magnet secured within said shank in spacedrelation to said non-circular opening, a sleeve of substantiallynonmagnetic material secured within said hollow shank and encompassing asubstantial portion of said magnet, and a hollow magnet extension pieceof magnetic material disposed in said sleeve with one end in associationwith one end of said magnet and the other open end protruding centrallyinto said nut receiving opening so as to normally retain a nut withinsaid opening by magnetic attraction and to receive the end of the bolt,upon which said nut is driven, within the open end thereof so that saidnut may be retained within said opening and simultaneously driven ontosaid bolt beyond the point where it is flush with the end thereof.

5. In a bolt clearance socket wrench having a shank with an opening inone end thereof adapted to receive ,a nut in driving relation, thecombination of a nonmagnetic sleeve, a magnet at least partiallyencompassed by said sleeve, and a magnet extension piece with an openingtherein adapted to receive a bolt onto which said nut is driven, saidextension piece having one end disposed in association with said magnetwith the opposite end extending into the opening in said shank.

References Cited in the file of this patent UNITED STATES PATENTS2,260,055 Reardon Oct. 21, 1941 2,678,578 Bonanno May 18, 1954 FOREIGNPATENTS 340,443 Germany Sept. 13, 1921 n w s

